A brake actuating system of this type is disclosed in EP 0 832 019 B1. The pressure control valves allocated to the wheel brakes in the prior art brake actuating system are configured as valves of a seat valve construction, arranged in pairs and being actuatable in an electromagnetic analog manner, and the inlet valves inserted in the connection between the pressure source and the wheel brakes are designed as normally closed seat valves that perform a pressure-limiting function in their closed switch position, while the outlet valves inserted in the connection between the wheel brakes and the pressure medium supply reservoir are designed as normally open valves that open the connection in their open switch position and shut it off in their closed switch position.
However, the above-mentioned publication does not indicate any measures that permit adapting the actuation characteristic curve of the pressure control valves to manufacture spread and aging effects as well as to changing environmental conditions.